Jake Heggie’s power­ful 2000 opera Dead ManWalking is get­ting its long-overdue UK premiere at the Barbican later this month. And, making this an unmissable event, that great American mezzo soprano Joyce DiDonato is singing the part of Sister Helen Prejean, a nun working with condemned prisoners.

The opera was composed in 2000, seven years after the publica­tion of Sister Prejean’s account of her work with prisoners on death row.

DiDonato has been closely involved with the opera for some while, not only taking on the role, but also meeting the indomitable campaigner against the death penalty. She acknowledges she’s been changed by the experience.

“You don’t meet Sister Helen, let along sing her, and leave unchanged,” she says in the Barbican’s latest Events publication. It’s led me to into a greater awareness of social justice and as opportunities to make a difference have come into my life, I’ve not been able to say ‘No’. Before meeting her, I felt pretty safe in my opinions about social justice. But when I met her, I saw next to me a human being who has encountered other human beings in such extreme situations.

“Not only murderers but also people who have been executed when they were innocent, the families of victims, the families of those executed.

“You don’t interact with a person like that and come away being comfortable with not getting involved. My experiences with Sister Helen and in the opera have woken this need in me to contribute, to help find solutions in the huge social justice issues that are all around us.”